North Korea Threatens to Resume Nuclear Work Without Sanctions Relief

Statement appears aimed at winning concessions from the U.S. in talks next week

SEOUL—North Korea warned on Friday it may revive a policy aimed at strengthening its nuclear arsenal if the U.S. doesn’t lift sanctions, signaling it won’t give up more concessions in nuclear negotiations with the U.S.

The comments came as friction has been growing between South Korea and the U.S. over how to use economic pressure in the effort to get North Korea to give up its nuclear weapons. South Korean President Moon Jae-in has said that economic development could provide an incentive to the North to disarm, while Washington...